Viral fusion is a validated mechanistic target for pharmacologic inhibition of HIV infection. Although the prototype therapeutic in this arena, enfuvirtide (Fuzeon, T20),is capable of suppressing HIV viral load in treatment-experienced patients, this peptidic drug suffers from the general drawbacks of traditional peptide therapeutics. These include loss of biologically-relevant secondary structure, a resultant decrease in bioactivity, and susceptibility to proteolytic degradation. Due to these and other challenges, including cost of goods and subcutaneous route of administration, pharmacologic approaches to HIV fusion inhibition are only deployed in refractory patients, rather than as an upfront approach to blocking viral infection. In addition, with incorporation of enfuvirtide therapy into the anti-HIV arsenal, resistance mutations have emerged. Here we propose the use of our novel chemical strategy, termed hydrocarbon-stapling, to generate "Stabilized Alpha Helices of gp41" (SAH-gp41) compounds for the investigation and targeting of HIV fusion, and for overcoming enfuvirtide resistance. Specifically, we aim to (1) synthesize diversified hydrocarbon- stapled gp41domains to optimize their biophysical properties, and (2) evaluate and optimize the capacity of SAH-gp41 compounds to target and inhibit HIV fusion. Although we choose gp41 as our prototype for fusion helix stabilization, the synthetic methodology and experimental strategies described herein have the potential for broad application in the analysis, prevention, and treatment of many types of viral infections. PUBLIC HEALTH RELEVANCE: HIV infection has created a public health crisis that threatens the lives of people across the globe and impacts the economic and societal well-being of world nations. There is an urgent need for new approaches to prevent and disrupt ongoing HIV infection. We propose an interdisciplinary approach that combines chemical biology and virology to generate a "chemical toolbox" to investigate and neutralize viral fusion, a critical step in the life cycle of the HIV virus.